library(shiny)
## RenderUI function..
shinyUI(fluidPage(
  titlePanel("Dynamic user interface - RenderUI"),
  sidebarLayout(
    sidebarPanel(
      
      selectInput(inputId = "data1",
                  label = "Select the Dataset of your choice", 
                  choices = c("iris","mtcars","trees"),
                  selected = "iris"),
      br(),
      helpText(... = "help info..."),
      br(),
      uiOutput(outputId = "vx"),
      br(),
      uiOutput(outputId = "vy")
    ),
    mainPanel(
      plotOutput("p")
    )
  )
))